Researchers have reported the clinical characteristics of five cases of Japanese spotted fever, a rickettsial infection, that occurred in the same region of Sichuan, China, over a short period. The case series, published in BMC Infectious Diseases, describes patients admitted from Dazhu County and surrounding areas between May and September 2025.
Japanese spotted fever is caused by Rickettsia japonica and is transmitted by ticks, though the exact route of exposure in these cases varied. All five patients had long-term residence in Dazhu and the surrounding endemic area. Four of the five reported outdoor exposure, while the single severe case had potential vector exposure within a domestic environment, where the presence of rodents was reported.
The study was designed as a descriptive analysis of a clustered case group. The authors collected data on epidemiological features, clinical manifestations, laboratory and auxiliary findings, treatment regimens and outcomes, with the aim of summarizing common points in diagnosis and management for similar cases.
All five patients presented with fever and rash, the hallmark features that prompted clinical suspicion. Among the four mild cases, the main additional findings were abnormal liver function and hypokalemia. The severe case followed a more aggressive course, with myalgia, diarrhea, septic shock and multiple organ dysfunction.
Laboratory abnormalities across the group included an elevated neutrophil percentage and increased C-reactive protein, along with raised alanine transaminase and aspartate transaminase levels. Chest CT imaging confirmed lung infection in the patients, indicating that pulmonary involvement was part of the clinical picture in this cluster.
Treatment centered on doxycycline in every case. Patients with mild disease received the drug as monotherapy or combined with piperacillin-tazobactam, together with symptomatic care such as hepatoprotective treatment and potassium supplementation. The severe patient required a more intensive regimen that additionally included platelet-elevating agents, fluid resuscitation, acid correction, anti-shock therapy, albumin and multi-organ support.
The outcome was favorable across the cluster: all five patients were cured after standardized treatment. The authors emphasize that early identification, targeted anti-infective therapy and multi-organ support are crucial for prognosis in Japanese spotted fever, and they describe their findings as supportive observations for regional rickettsial infection prevention and control.
As a small case series from a single region, the report cannot establish treatment efficacy or generalizable risk estimates, and the article is being shared ahead of final editorial production. Nevertheless, the cluster offers a detailed picture of how Japanese spotted fever presented in this part of Sichuan, including the observation that severe disease can arise without documented outdoor exposure, and it underscores the importance of considering rickettsial infection in febrile patients with rash from endemic areas.
Subject of Research: Clinical characteristics and treatment of five Japanese spotted fever cases in Sichuan, China
Article Title: Clinical characteristics analysis of five cases of Japanese spotted fever rickettsia infection
Article References: Liu, J., Wu, Q., Cai, H., Tang, M., Sun, H., Shi, G., Chen, J., Xia, F., Zhou, X., Xin, J., & Yang, X. (2026). Clinical characteristics analysis of five cases of Japanese spotted fever rickettsia infection. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14301-7
Image Credits: AI Generated
DOI: 10.1186/s12879-026-14301-7
Keywords: Japanese spotted fever, rickettsial infection, Rickettsia japonica, doxycycline, case series, Sichuan, Dazhu County, fever and rash, septic shock, liver function abnormalities, tick-borne disease, BMC Infectious Diseases
News Source: Ophelia Keating. (October 28, 2026). Five Japanese Spotted Fever Cases in Sichuan Show Early Doxycycline Key to Recovery. Scienmag.
